RBC I Technical Advisory Team Met Dec. 14
Callie Hendrickson, executive director of the White River and Douglas Creek Conservation Districts, kicked off the Dec. 14 meeting of the USGS-led Algae Study Technical Advisory Group (TAG). Representatives from some 13 local, state and federal government agencies plus one citizen’s group, Trout Unlimited, comprise the group. The primary purpose of the meeting was to discuss apparent results of the study to date and focus on possible changes in the scope of work for USGS going into the study’s second year.
USGS research principals Michael Stevens and Natalie Day (Grand Junction and Moab, Utah), highlighted preliminary indications of nutrient level concentrations as well as “flux” trends, based on river sampling and review of data back to 1999. They explained that concentrations were point sample (water column) values while flux values show how much of a given nutrient is delivered downstream over a period of time.
Indications are that during the 18-year period studied, nitrogen concentrations downstream of Meeker were actually lower, probably due to improved water treatment by the Meeker Sanitation District. Values during high water months upriver were definitely greater with more nutrients being carried downstream—perhaps by as much as 13 percent. The big surprise, Day reported, is phosphorus loading. So much so that any algae growth would not be limited by there not being enough phosphorus. Nitrogen source testing has been frustrated, and may be prevented, by there simply not being enough nitrogen present to do the isotopic analysis USGS had planned.
Temperature Increases Earlier in Year Concerning
Temperature data is also interesting, even though the sampling consistency of temperature data over time is a challenge. It appears temperatures are up only very slightly for the normal highs of August, but they are up significantly earlier in the summer season and for a longer period of time. USGS plans to further analyze the data and intensify their sampling for this in 2019. It was noted that these temperature changes appear quite compelling.
Dissolved oxygen tests definitely showed higher highs and lower lows, partially confirming greater in-stream biomass activity (metabolism). The green algae bloom in the river this past summer did not develop to the degree it has in the last few years, but a second bloom of some extent in August did surprise researchers. The extent of the green algae Cladophora in the river system was much greater than expected as the algae was found to some degree at every test site, even those further upriver that were supposed to be reference sites for no Cladophora.
The USGS team discovered a greater mix of other (non-green) algae and both aquatic and terrestrial mosses, making the whole system more complicated than perhaps expected and creating the need to do more taxonomic evaluations this coming year. Other topics suggested for greater attention in 2019 were increased water quality sampling, peak flow and scouring analysis.
USGS also identified the need for more photographic work to be done by local personnel in order to record algae changes. Efforts to record these types of changes by remote cameras in 2018 were not successful.
Day suggested the phosphorus loading could well be from increased regional aridity in recent years, being deposited by prevailing winds in the higher forest and snowpack. She commented that this is nearly a global phenomenon, not limited to the White River Basin.
River Disturbances to be Looked at More Carefully
In response to continued concern about nutrient loading due to disturbance from dredging and other river manipulation, USGS indicated they have looked at that question and intend to look at it more carefully. Also mentioned by USGS was that one landowner had requested that sampling data from their stretch of water not be used, so that data has been withdrawn.
Long-standing local River Watch Program coordinator Dr. Bob Dorsett commented that given the lower flows, the consistently higher and longer-lasting high temperatures, with peak run-off being 22 days earlier than on average 50 years ago, it’s apparent we are definitely suffering from the effects of climate change with which we are rather stuck, but that we have to do what we can to counteract.
Tory Eyre, local Colorado Parks and Wildlife fisheries biologist, reported that CPW had engaged in increased biological testing and surveillance on the river, in cooperation with USGS and Trout Unlimited, but that their data will not be fully processed until perhaps April. Eyre did mention increased algae presence in one locale where mosquito spraying had occurred.
The Lake Avery releases, he reported, dropped Avery levels by more than 7-½ feet, but that the lake level had already recovered to a large degree. The temperature extreme for the summer was reported to be almost 80 degrees (on July 22) at Meeker’s Circle Park while the flow level dropped to just under 18 cubic feet per second (cfs) at the Wakara Bridge on Aug. 16, during the daily release of 20 cfs from Avery. Twenty cfs is supposed to be the minimum flow for the White here. There is a question of whether or not the colder but nutrient-loaded water from the bottom of the Avery dam might have played a role in the secondary bloom in August.
TAG Meets Again Jan. 8
Hendrickson cataloged the ongoing issues identified in the meeting and said the TAG will continue to review the 2019 Scope of Work for the USGS study—a task she expects them to complete by March 1. A follow-up meeting of the TAG in this regard has been set for Tuesday, Jan. 8, 1-4 p.m., in the Sheriff’s Office training room in Meeker.
First year expenditures for the study were budgeted to be about $120,000 and are planned to be about $139,000 for 2019. A big piece of the 2019 money, some $41,000, is coming through the Yampa-White-Green Basin Roundtable. TAG member Alden Vanden Brink, Rio Blanco Water Conservancy District manager of Rangely, and Roundtable co-vice chair, commented that the Roundtable has been very impressed with how quickly and significantly the collective county group here had jumped on the algae issue.
Some 13 individuals representing 11 of the 14 TAG member organizations, a couple staff and 10 various members of the public attended the meeting. County commissioner Jeff Rector, who represented RBC on the TAG for this meeting, said he feels the TAG has done a great job and that he hopes carrying on the USGS study with a revised scope of work in 2019 will turn up some answers for 2020.
By REED KELLEY | [email protected]
